Catalyst deactivation in the gas phase destruction of nitrogen-containing organic compounds using TiO2/UV-VIS

Possible application of the TiO2/UV-VIS photocatalytic process in the destr uction of nitrogen-containing malodorous compounds was evaluated. Pyridine (C5H5N), propylamine (C3H7NH2) and diethylamine (C4H10NH) were photodegrade d in the presence and in the absence of oxygen. Degradation of nitrogen-con taining organic compounds was confirmed by mass balance taking into conside ration NH4+ and NO3- ions trapped at the TiO2 surface. Photocatalytic deact ivation was observed in all cases. On-line mass spectrometry was used to id entify byproducts in the gas phase formed during the degradation process. G C-MS analysis of the dichloromethane-extract of aqueous species leached fro m the surface of deactivated catalyst, as well as pre-concentration in a Te nax column were used to identify intermediates in the gas phase. These bypr oducts are considered to be the major ones responsible for deactivation of TiO2. (C) 2001 Elsevier Science B.V. All rights reserved.